A. Hossienpour Zelaty - International Caspian Sturgeon Research Institute, Agricultural Research, Education and Extension Organization (AREEO). Rasht. PO Box: ۳۴۶۴-۴۱۶۳۵
M.H. Seyed Hassani - International Caspian Sturgeon Research Institute, Agricultural Research, Education and Extension Organization (AREEO). Rasht. PO Box: ۳۴۶۴-۴۱۶۳۵
T. Sohrabi - International Caspian Sturgeon Research Institute, Agricultural Research, Education and Extension Organization (AREEO). Rasht. PO Box: ۳۴۶۴-۴۱۶۳۵
F. Bagherzadeh Lakani - International Caspian Sturgeon Research Institute, Agricultural Research, Education and Extension Organization (AREEO). Rasht. PO Box: ۳۴۶۴-۴۱۶۳۵
M. Mohseni - International Sturgeon Research Institute, Iranian Fisheries Science Research Institute (IFSRI), Agricultural Research, Education and Extension Organization (AREEO), Rasht, Iran
Z. Pajand - International Sturgeon Research Institute, Iranian Fisheries Science Research Institute (IFSRI), Agricultural Research, Education and Extension Organization (AREEO), Rasht, Iran

The aim of this study was to investigate the effects of dietary supplementation of a commercial probiotic containing Bacillus subtilis, Lactobacillus acidophilus, L. delbrueckii, L. rhamnosus, and L. plantarum on growth performance, hematological and immunological parameters of bester fingerlings. Two-hundred and forty fingerlings (۱۰±۰.۹ g) were randomly distributed into ۱۲ fiberglass tanks. The experimental diets were formulated using ۰ (control), ۱۰۰ (T۱۰۰), ۲۰۰ (T۲۰۰), and ۳۰۰ (T۳۰۰) mg/kg of the probiotic. The fish were fed at ۳% of body weight for ۸ weeks. The result revealed that dietary probiotics increased final weight, condition factor, daily growth rate, specific growth rate, and body weight increase (p>۰.۰۵). Also, we observed a significant increase in feed efficiency ratio and protein efficiency ratio for fish fed with T۳۰۰ compared to T۲۰۰ (p<۰.۰۵). Hematological parameters were not influenced by dietary probiotic levels (p>۰.۰۵). There were no significant differences in total immunoglobulin (p>۰.۰۵), while alternative complement activity was significantly enhanced by the inclusion of probiotics in diets (p<۰.۰۵). The present study showed that feed efficiency, protein efficiency, and immunological parameters of bester fingerling have been improved by adding the commercial probiotic at ۲۰۰ mg/kg.

Probiotic, Bester, Growth, Hematological parameters, Immunological Parameters